Risk analysis of Bacillus spp. isolated from cured pork sausages

This study was undertaken to acquire information about the toxigenic potential of Bacillus strains isolated from eight cured pork sausages obtained from traditional or industrial processings. The application of RAPD-PCR protocols made it possible to identify 52 different biotypes among 220 heat-resistant Gram-positive endospore-forming colonies. The sequence analysis of the 5’ region of 16S rDNA revealed that 36 strains belonged to B. subtilis and 16 to B. pumilus species. No strains belonging to B. cereus species were isolated from the cured sausages analysed. The toxigenic potential of these strains was assayed by PCR analysis and physiological tests to identify the most important B. cereus toxins and virulence factors. No specific PCR fragment was obtained from any of the strains; however, some of them were found positive for hemolytic and lecithinase activity.These preliminary results reassure about the microbiological risk related to the presence of pathogenic Bacillus strains in cured pork sausages analysed even though the hemolytic and lecithinase activities found in some strains suggest that more in-depth analyses need to be carried out

Design and characterization of a novel fermented beverage from lentil grains

The experimental activities carried out in this study aimed at designing a lentil-based beverage rich in soluble and digestible proteins. In order to extract soluble proteins, lentil grains were soaked in water overnight, blended, treated with proteolytic enzymes and fermented with Lactobacillus strains. Protein enzymatic hydrolysis, carried out with four commercial food grade enzyme preparations, showed that bromelin, at the enzyme to substrate ratio of 10%, was the best solution to produce this novel beverage. Even though the seven Lactobacillus strains were all able to ferment aqueous extract within 24 h, L. acidophilus ATCC 4356, L. fermentum DSM 20052 and L. paracasei subsp. paracasei DSM 20312 showed the highest growth rate and the lowest pH values. In fermented lentil-based beverages, the antinutritional factor phytic acid decreased up to 30%, similarly, the highest reduction in raffinose oligosaccharides content reached about 12% the initial concentration. It is worthy of note that the viable density of all strains remained higher than 7 log cfu/mL after 28 days of cold storage. The results here reported show for the first time the possibility to obtain a probiotic lentil-based beverage rich in soluble proteins, peptides and amino acids with low content in main antinutritional factors

Use of selected lactic acid bacteria for the fermentation of legume-based water extracts

In this study, the effect of selected Lactobacillus acidophilus ATCC 4356, Limosilactobacillus fermentum DSM 20052, and Lacticaseibacillus paracasei subsp. paracasei DSM 20312 strains on the sensory characteristics, and protein and amino acid content of fermented water extracts derived from lupin, pea, and bean grains is reported. Even though all strains were able to grow over 7 log cfu mL(-1) and to decrease pH in the range of -0.52 to -1.25 within 24 h, the release of an unpleasant ferric-sulfurous off-odor from the fermented bean water extract prohibited further characterization. Lupin and pea grain-based beverages underwent an in-depth sensory evaluation using a simplified check-all-that-apply (CATA) method, finding new and appreciable sensory notes such as cooked ham, almonds, and sandalwood. Fermented lupin water extract showed higher total protein content (on average, 0.93 mg mL(-1)) in comparison to that of pea grains (on average, 0.08 mg mL(-1)), and a free amino acid content (on average, 3.9 mg mL(-1)) close to that of cow milk. The concentrations of these nutrients decreased during refrigerated storage, when the lactic acid bacteria load was always higher than 7 log cfu mL(-1). The results of this study indicated that lactic fermentation improves the sensory characteristics of these innovative legume-based beverages, which sustained high loads of viable lactobacilli up to the end of cold storage

IDIOPATHIC PARTIAL EPILEPSY WITH AUDITORY FEATURES (IPEAF): A CLINICAL AND GENETIC STUDY OF 53 SPORADIC CASES

The purpose of our study was to describe the clinical characteristics of sporadic (S) cases of partial epilepsy with auditory features (PEAF) and pinpoint clinical, prognostic and genetic differences with respect to previously reported familial (F) cases of autosomal dominant partial epilepsy with auditory features (ADPEAF). We analysed 53 patients (24 females and 29 males) with PEAF diagnosed according to the following criteria: partial epilepsy with auditory symptoms, negative family history for epilepsy and absence of cerebral lesions on NMR study. All patients underwent a full clinical, neuroradiological and neurophysiological examination. Forty patients were screened for mutations in LGI1/epitempin, which is involved in ADPEAF. Age at onset ranged from 6 to 39 years (average 19 years). Secondarily generalized seizures were the most common type of seizures at onset (79%). Auditory auras occurred either in isolation (53%) or associated with visual, psychic or aphasic symptoms. Low seizure frequency at onset and good drug responsiveness were common, with 51% of patients seizure-free. Seizures tended to recur after drug withdrawal. Clinically, no major differences were found between S and F patients with respect to age at onset, seizure frequency and response to therapy. Analysis of LGI1/epitempin exons failed to disclose mutations. Our data support the existence of a peculiar form of non-lesional temporal lobe epilepsy closely related to ADPEAF but without a positive family history. This syndrome, here named IPEAF, has a benign course in the majority of patients and could be diagnosed by the presence of auditory aura. Although LGI1 mutations have been excluded, genetic factors may play an aetiopathogenetic role in at least some of these S cases

Differentiation of Pseudomonas syringae subsp. savastonoi strains isolated from various host plants by restriction fragment lengh polymorphism

A 1.8 kb DNA fragment encoding a putative protein similar to precorrin-3 methylase, a protein of Pseudomonas aeruginosa involved in cobalamin biosynthesis, was cloned from an olive strain of the plant pathogenic bacterium Pseudomonas syringae subsp. savastanoi. This fragment, potentially involved also in virulence, methionine prototrophy and ability to elicit a hypersensitive response, was used as a probe for detecting restriction fragment length polymorphism (RFLP) in 52 strains of P. s. subsp. savastanoi isolated from olive, oleander and ash. Southern blot analysis revealed a single strongly hybridizing band in all P. s. subsp. savastanoi strains and EcoRI polymorphism was detected among strains isolated from olive plants. In addition, when HindIII was used as a restriction enzyme, the P. s. subsp. savastanoi strains isolated from olive clearly differed from those isolated from oleander and ash on the basis of the size of a single hybridizing band. This clear difference between the strains isolated from olive and those isolated from oleander further supports the hypothesis that the populations of P. s. subsp. savastanoi which infect the above-mentioned host plants differ from one another

Innovative eco-friendly hydrogel film for berberine delivery in skin applications†

Hydrogel formulations (masks or patches, without tissue support) represent the new frontier for customizable skin beauty and health. The employment of these materials is becoming popular in wound dressing, to speed up the healing process while protecting the affected area, as well as to provide a moisturizing reservoir, control the inflammatory process and the onset of bacterial development. Most of these hydrogels are acrylic-based at present, not biodegradable and potentially toxic, due to acrylic monomers residues. In this work, we selected a new class of cellulose-derived and biodegradable hydrogel films to incorporate and convey an active compound for dermatological issues. Films were obtained from a combination of different polysaccharides and clays, and berberine hydrochloride, a polyphenolic molecule showing anti-inflammatory, immunomodulatory, antibacterial and antioxidant properties, was chosen and then embedded in the hydrogel films. These innovative hydrogel-based systems were characterized in terms of water uptake profile, in vitro cytocompatibility and skin permeation kinetics by Franz diffusion cell. Berberine permeation fitted well to Korsmeyer–Peppas kinetic model and achieved a release higher than 100 µg/cm2 within 24 h. The latter study, exploiting a reliable skin model membrane, together with the biological assessment, gained insights into the most promising formulation for future investigations

Desarrollo de un biosensor enzimático para la detección de acetaldehído en saliva

El consumo de tabaco y alcohol representa el mayor factor de riesgo para el desarrollo de cáncer bucal. La identificación de compuestos carcinógenos contribuye al reconocimiento de grupos vulnerables. Luego de la ingesta de etanol y consumo de tabaco, se genera y acumula acetaldehído en saliva. OBJETIVO: Desarrollar un biosensor enzimático para la detección de acetaldehído en saliva que presente ventajas respecto a los métodos convencionales de cuantificación (cromatografía gaseosa). METODOLOGIA: El biosensor desarrollado se basa en la actividad de la enzima aldehído deshidrogenasa (AldDH), que se inmoviliza en una matriz proteica. Cuando esta enzima se encuentra en presencia de acetaldehído, ocurre una reacción redox en la cual el acetaldehído se oxida a ácido acético y el cofactor de la enzima (NAD+) se reduce a NADH, siendo su concentración proporcional a la de acetaldehído. Por lo tanto, se estudiaron diferentes técnicas para sensar NADH como primer abordaje. La más efectiva fue la inclusión de monómeros redox adsorbidos en una matriz de mucina y nanotubos de carbono. En una segunda etapa, se incorporó la AldDH inmovilizada en matrices proteicas, compuestas por albúmina, mucina, quitosán y sus mezclas en distintas proporciones. Se utilizó glutaraldehido como entrecruzante. Con estas matrices se preparó un biosensor tipo sándwich, incluyéndolas entre dos membranas de policarbonato sujetadas por un capuchón plástico. RESULTADOS: Una vez logradas las condiciones óptimas, se realizaron curvas de calibración y se evaluó la relación entre la sensibilidad, estabilidad e intervalo de linealidad en función de la composición, grado de entrecruzamiento de la matriz, pH y fuerza iónica. El potencial seleccionado fue 0,1 V, y el pH de trabajo 8,0. Se obtuvo un buen intervalo de linealidad, con una sensibilidad igual a 3,0 µA/mM, límite de detección de 7µM, y una estabilidad mayor al 80% de aproximadamente un mes. Se observó, además, que los componentes presentes en la saliva no producen interferencia. CONCLUSIONES: Se desarrolló un biosensor económico en cuando a reactivos y equipamiento utilizados, de sencilla fabricación y con una performance analítica aceptable respecto a la metodología tradicional para la cuantificación de acetaldehído.Fil: Berasategui, Lucía. Universidad Nacional de Córdoba. Facultad de Odontología; Argentina.Fil: Comba, F. Universidad Nacional de Villa Maria. Departamento de Fisicoquimica; Argentina.Fil: López de Blanc, Silvia. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Estomatología B; Argentina.Fil: Baruzzi, Ana María. Universidad Nacional de córdoba.Facultad de Ciencias Químicas. Departamento de Fisicoquimica; Argentina.Patologí

eoagulase nega tive-sta phylococci and enterococci in fermented meat products: presence of virulence and antibiotic resistance determinants

This study was undertaken to achieve information on the presence of antibiotic resistance determinants in coagulase negative staphylococci (CNS) and enterococci (Ec) that are a significant component of the fermentation process of cured meat products. Vancomycin resistant Ec and CNS were isolated thorough the production process from raw pork meats to final products and, furthermore, many Ec strains were found to be positive in PCR experiments for jsrA and ace, virulence expression factors